Key Diagnostic Rules:

• When subcool readings allow TXV diagnosis
• The critical superheat thresholds (normal vs. problematic)
• How to use split temperatures to confirm your diagnosis

Troubleshooting:

• How to test if a TXV is actually stuck vs. slightly restricted
• The hand-on-bulb test technique for verification
• Distinguishing between TXV failure and compressor slipping
• Open TXV scenarios and what they reveal

Real-World Applications:

• Compressor slipping vs. TXV overfeed diagnosis
• Airflow issues that mimic TXV problems
• When adding refrigerant helps vs. when it doesn’t

Tips Covered:

• Why superheat alone isn’t enough for diagnosis
• Using subcool readings as your diagnostic gateway
• The importance of split temperature verification
• Heat pump mode testing for stuck TXVs